It is very simple. Go up the office and stand face the man here. Push action button ( right mouse button usually ) and click a model name. The you can wait your favorite color go up then use "tabulator" button and the car now is yours. The base mafia setting are the correct in this case. Good luck

Great news
Many thanks to Priatnia2 because his game settings to fix of 60's mod crash works well in Ikarus mod 3.0 too. I tested it.
If you have running problems or have unfortunately nvidia card, this can helps you surely. The only the car shining will lost but every other ability of IKM3 mod remain and work well without crash but little bit with lower frame rate. If you are in big trouble to run IKM3 mod, somehow this helps. Thanks again old mate Priatnia2.